1. Field of the Invention
This invention relates to an intravenous catheter introducing device, more particularly to an intravenous catheter introducing device with a needle cannula which is retractable into a tubular plunger for safe disposal.
2. Description of the Related Art
Intravenous catheter introducing devices are generally used to administer a medication fluid into or to draw blood from a patient's vein. Referring to FIG. 1, a conventional intravenous catheter introducing device 9 is shown to include a tubular needle seat 91 with a hub end 911, a needle cannula 94 secured to the hub end 911, a catheter hub 92 sleeved on the needle seat 91, and a flexible tubular catheter 93 secured to the catheter hub 92. In use, the catheter 93 and the needle cannula 94 are inserted into the patient's vein by a health care worker by piercing the patient's vein with a sharp tip of the needle cannula 94 which projects outwardly of the catheter 93. The health care worker then withdraws the needle cannula 94 from the catheter 93 with one hand and, at the same time, applies pressure to the patient's skin with the other hand, thereby leaving the catheter 93 in the patient's vein. Subsequently, a transfusion member (not shown) with the medication fluid or an empty barrel is connected to the catheter hub 92 for administering the medication fluid into the patient's vein or for drawing blood. At this time, the exposed sharp tip of the used needle cannula 94 may create a danger of an accidental needle stick.
Moreover, the conventional intravenous catheter introducing device 9 is specifically not suitable for patients whose blood pressure is not sufficient to permit flow of blood therethrough, such as an emergency case, aged people, and pediatrics patients, and patients whose target vein is barely visible due to abundant adipose tissue, such as women and obese patients, since the health care worker will have difficulty determining whether the catheter 93 has been successfully introduced into the target vein, and may need to locate the vein by moving the needle cannula 94 in the skin of the patient, thereby complicating and prolonging the cannulation procedure and causing great discomfort to the patient.
Furthermore, although conventional self-retracting IV catheter introducers permit self-retraction of the used needle cannula into the syringe barrel after introduction of the catheter is completed, the blood in the barrel may be forced out of the barrel during the retraction of the used needle cannula so that blood contamination may occur.